outliner : to cycle the find result in outliner
Not exactly a 'Find Next' .. but there's a dropdown next to the Filter checkboxes which can restrict the outliner display, to, among others, only selected objects.
I've assigned that dropdown to the Numpad / key, analagous to isolating in the 3D view. 'Selected' restricts the outliner view to (all) references to objects selected in the viewport.